Note:
Debian/Ubuntu users may have to `sudo rm -f /etc/shadowsocks` before install
the new `shadowsocks-libev` package.
For library user, the pkg-config package is renamed to `shadowsocks-libev` but
the library name is still the `libshadowsocks` (use `-lshadowsocks` to link)
Should be built against MinGW, and please note that
only ss-local is ported due to lack win32 support of
libasyncns. And libev doesn't support IOCP but only
supports select